Rotary automobile crane



Oct. 27, 1959 Filed Aug. 2, 1957 H. SCHEUE RPFLLQJG 2,910,1 9

ROTARY [AUTOMOBILE CRANE fig. 1

3 Sheets-Sheet l INVENTOR HANS SCHEUERPFLUG ATTORNEYS 1959. i H; 'SCHEU RPFLUG I 2,910,189

;,R0TARY AUTOMOBILE CRANE;

- Filed Aug. 2, 1957' 3 Sheets-Sheet 2 fig. 2

I INVENTOR HA NS SCHEUERPFLUG BY 74ml.

ATTORNEYS United States Patent ROTARY AUTOMOBILE CRANE Hans Scheuerpflug, Numberg, Germany, assign'or to ,MAN Maschinenfabrik Augsburg-Numberg-AG, Number-g, Germany The present invention relates to rotary cranes. More in particular the present invention relates to rotary automobile cranes having an adjustable boom.

In the known rotary automobile cranes the adjustable boom is mounted in the boom. bearing in the lower portion of the upper chassis and as far as possible towards the counter balancing side and it is stayed by the guys and the lufiing gear.

The load applied to the crane acts upon the rotatable upper chassis via the boom, the guys and the luffing gear and the forces acting upon the upper chassis are transferred to the lower chassis via a ball turning connection joining the lower and the upper chassis. The ball turning connection is positioned approximately in the center of the lower chassis and this connection is subjected to considerable bending forces. In order to avoid excessive tensions and to reduce the overall dimensions of the crane, usually a medium load moment is chosen with reference to the possible pitching moments of the crane. This leads to the undesirable result ofa limited loading capacity of the crane.

The loading capacity of a crane can be increased by increasing the angle formed by the boom and the guys. However, an increase of this angle meets with difiiculties since the boom should be allowed to freely extend from the crane in order to increase its range of operation and in view of the fact that the upper chassis should require a minimum of space.

V It has been tried to increase the load capacity of a rotary automobile crane by increasing the angle formed by the boom and the hoisting line. The load capacity of the crane is increased in'the direction of the longitudinal axis of the motor vehicle without reinforcement of the boom and the lufiing gear and without subjecting the ball turning table and the lower chassis to a substantial supplementary load, This is eifected by providing bearings on the lower chassis and transferring the fulcrum-of the boom from the upper chassis to these bearings on the lowerchassis whenever the boom assumes a position pointing in the direction of the longitudinal axis of the lower chassis, thereby increasing the angle between the boom and the hoisting line. ll.Although the load capacity of the crane is augmented byzthe crane construction just described the upper chassis cannot be turned and the maneuverability of the crane is thus greately impeded. 1. It is an object of the present invention to provide a rotary automobile crane having an increased load capacity. It is another object of the present invention to provide a rotary automobile crane which has an increased load capacity and in which the upper chassis can be turned relative to the lower chassis.

It is still another object of the present invention to provide a rotary automobile crane havingv an increased load capacity in which the upper chassis can be swung through a full circle evenlif the maximum load is applied to the crane and in which the stability of the lower piece 6, instead of in the bearing 2. Thereby the angle 2,910,189 Patented Oct. 27, 1959 chassis is increased in accordance with the additional load capacity of the crane. V I

These objects are achieved by the rotary automobile crane of the present invention comprising an intermediate piece interposed between the boom and the hoisting line. This intermediate piece is provided with a hearing at its one end with which the intermediate piece is 'posi tioned in the bearing at the upper chassis originally provided for positioning the boom. At its other end the intermediate piece is provided with another bearing connected to the lower end of the boom. After the intermediate piece has been inserted the boom can be turned together with the upper chassis.

According to another feature of the invention the crane is provided with means directly transferring to the lower chassis the vertical component of the force of the load acting upon the boom.

The rotary automobile crane of the invention can be provided with supporting rail means further increasing the range in which the upper chassis and the boom can be turned relative to the lower chassis, and preferably with means whereby the upper chassis can be swung through a full circle.

The crane can also be provided with means for supporting the lower chassis in order to increase its stability as required by the additional load capacity of the crane.

, According to a further feature of the invention lifting and tensioning means are provided whereby the upper chassis comprising the intermediate piece can be swung through a full circle even if the above-mentioned supportingrail means for increasing the range in which the upper chassis can be turned are not available.

According to another preferred embodiment of the invention there are provided tensioning means whereby the upper chassis including the intermediate piece can be swung through a full circle, even if the above-mentioned supporting rail means for increasing the range in which the upper chassiscan be turned are not available, and even if loads not exceeding a'predetermined weight are applied to the crane.

The invention also envisages the provision of means for preventing an overloading of the rotary automobile crane.

The present invention will be better understood upon the following detailed description of the accompanying drawings, wherein Figure l is a lateral view of the rotary automobile jcrane of the present invention with one embodiment of the tensioning device of the invention;

Figure 2 is a lateral view of the rotary automobile crane of the present invention with another embodiment of the tensioning device of the invention;

' Figure 3 is a plan view of the rotary automobile crane shown in Figures 1 and 2 without the tensioning device;

Figure 4 is a plan view of another embodiment of the lower chassis of the rotary automobile crane of the invention.

Referring now to the drawings more in particular, the rotary automobile crane comprises an upper chassis 3, a lower chassis 4, a boom 1, and a hoisting line 5.

In conventional rotary automobile cranes the boom 1 is positioned in the bearing 2 of the upper chassis 3 and thereby connected to the latter. The upper chassis 3 can be turned upon the lower chassis 4, usually through a full circle of 360.

According to the present invention, the rotary automobile crane comprises an intermediate piece 6 which is positioned with one of its ends in the bearing 2 originally provided for the boom 1. The boom 1 is positioned in the bearing 7 at the other end of the intermediate between the boom 1 and the hoisting line 5 is increased, which results in a greater load capacity of the crane.

The rotary automobile crane is also provided with means for directly transferring to the lower chassis the vertical component of the force of the load acting'upon the boom, which may consist of rolls 8 mounted upon the intermediate piece 6 in the immediate vicinity of the bearing 7. The lower chassis 4 is provided with rails 9 supporting the rolls 8 upon the intermediate piece '6.

The upper chassis can be turned by an angle of approximately 50 if the boom points forward or backwardly in the direction of the longitudinal axis of the vehicle, with the rolls 8 of the intermediate piece of the upper chassis traveling in the rail 9 of the lower chassis.

This limitation of the swinging range of the crane results from the limited width of the chassis of the automobile crane which cannot be increased beyond a certain amount generally allowed for motor vehicles. It is, however, possible to increase the swinging range in which the upper chassis and the boom can be turned relative to the lower chassis by means of the platforms 11 and 11a arranged laterally on both sides of the lower chassis 4, and which bear rails 12 and 12a constituting an extension of the rail 9.

Another embodiment of the lower chassis 3 of the rotary automobile crane of the invention is shown in Figure 4 of the drawings in which the rails for the rolls 8 of the upper chassis 4 form a full circle so that the upper chassis can be swung by 360;

The lower chassis 29 has a support 27a at its front end 29a and another support plate 27!) at its rear end 296. At both sides of its central portion 29c the lower chassis 29 is provided with laterally extensible supports 26a and 2612. After having extended laterally the supports 26a and 26b their respective outer ends can be connected with the respective outer ends of the support plates 27a and 27b by support bridges 28a, 28b, 28c, and 28d. Thereby a hexagonal support is obtained which is formed by the support plates 28a, 27a, 28b, 23c, 27b, and 27d. Upon this hexagonal support there is mounted the circular guide rail 30adapted to receive the rolls 8 of the upper chassis of the rotary crane. The upper chassis can thus be swung through a full circle While the maximum load is applied to the crane, including the supple mentary load applicable after insertion of the intermediate piece 6. The necessary stability of the lower chassis 29 is assured by support plates 31, 31a, 31b, 31c, 31a, 31e, 311, 31g, 31k, 311, and 31k, mounted upon the hexagonal support on the respective lower sides of the support members 28a, 27a, 28b, 28c, 27!), 28d, respectively. p

The increased load capacity of the rotary automobile crane of the present invention exceeds the stability of the lower chassis and for that reason means are provided for increasing this stability which may consist of support plates 10 mounted upon the lower chassis 4 underneath the rail 9. The support plates come to rest upon the floor and support the lower chassis of the rotary crane. The vertical component of the load acting upon the boom 1 is thus directly transferred to the floor via the intermediate piece 6, the rolls 8 of the upper chassis 3 and then via the rail 9 and the support plate 10, of the lower chassis 4. If the rotary automobile crane has lateral platforms 11, additional support plates 13 support the platforms with the rails 12 along which the upper chassis and the boom with the load is allowed to travel.

The rotary automobile crane of the present invention can also be provided with means which make it possible to swing the upper chassis with the boom through a full circle of 360 upon the lower chassis even if there are no platforms 11 with rails 12 extending the limited swinging range of the upper chassis, or in case the platforms with the rails 12 are not sufiiciently large to: permit the upper chassis to travel upon these rails through a full circle. For this purpose, the rotary automobile crane 4 is equipped with a te'nsioning device. One embodiment of this tensioning device is shown in Figure l and comprises the line 14 and supporting frame 15 mounted upon the upper chassis 3, and bearing on its top end the pulley 17. Another pulley 16 is mounted upon the left end of the intermediate piece 6, Le. the end having the bearing 7 for the boom 1, and a winch 18 is mounted at the upper chassis 3. The line 14 extends between the frame 15 and the winch 18 and is led over the pulleys 16 and 17.

The upper chassis can be turned around a fullcircle after the rolls 8 have been lifted from the corresponding rails 9 by manually turning the winch 18. The intermediate piece 6 is held in its position relative to the upper chassis 3 by the pull of line 14 and the upper chassis can now be turned by 360, provided the crane does not carry a load.

It may be desirable to swing the upper chassis around a full circle while loads of comparatively. light weight are carried by the crane, and in case-the platforms are not suflicient to permit of such a swinging range,-or where no platforms are available at all. This is made possible by another embodiment of the tensioning device of the rotary automobile crane of the present invention illustrated in Figure 2 of the accompanying drawings.

The tensioning device comprises a frame 19 having a strut 19a and a strut 1% connected with their respective lower ends to the intermediate piece 6 at 19c and 19d, respectively. The frame 19 is connected to the upper chassis 3 via a resilient strut 20 provided with a spring 24. A pulley 21 is mounted at the top of the frame 19 and forms a part of the tackle 22 connecting the hoisting line 5 with the upper chassis 3. The distance of the rolls 8 of the intermediate piece6 from their respective, corresponding rails therefore depends upon the load moment. If a light load or no load at all is applied to the boom l, the rolls 8 are out of contact with'the' rails and the upper chassis can be swung through a full circle. The spring 24 of the resilient strut 20 can be so adjusted that the rolls 8 exactly assume the contacting height relative to the rails as soon as the load moment reaches the maximum value admissible for rotatingthe upper chassis 3 without the additional support of the intermediate piece 6 If the load exceeds a certain, predetermined value the upper chassis 3 with the intermediate fiiec'e'6 is lowered against the tendency of resilient strut 20 and the rolls 88 of the intermediate piece come intocontact with the rails.

The rotary automobile crane of the present invention and particularly the rotary automobile crane having the tensioning device just described, can be provided with means preventing overloading of the crane which may consist of switch means connected to the intermediate piece or the tensioning device, for example a switch 23 mounted on the intermediate piece 6 of the upper chassis 3, and switching in or switching 05 the driving means of the crane according to the particular height of the roll of the intermediate piece above the corresponding rails. As has already been mentioned, the spring 24 of the resilient strut 23 can beso adjusted that the rolls 8 exactly assume the contacting height relative to the fails as soon as the ioad moment reaches the maximum value admissible for rotating the upper chassis 3' withoutthe additional support of the intermediate piece 6. If in this situation the rolls 8 do not happen to, accurately assume a position directly above their corresponding railsthe switch 23 mounted upon the intermediate piece 6' shuts off the driving means of the crane. If the rolls 8 are accurately positioned directly above their corresponding rails so as to exactly come to rest'upon the latter the switch 23 is put out of operation by a control switch 25 sliding along the rails 9' and 12. p v

It will he understood that this invention is susceptible to modification in order to adapt' it' to dilfe'ren't usages and conditions and, accordingly, it isdesired to comprehend such modifications within this invention as may fall within the scope of the appended claims.

What I claim is:

1. A rotary automobile crane comprising a lower chassis, an upper chassis having a bearing and being rotatably arranged upon said lower chassis, an intermediate piece pivotally connected at its one end to said bearing of said upper chassis, a boom pivotally connected at its lowermost end to the opposite end of said intermediate piece, and holding means acting independently of said boom for holding said intermediate piece in a generally horizontal position.

2. A rotary automobile crane as described in claim 1, wherein said holding means comprise supporting means associated with said intermediate piece in the region of said opposite end thereof for supporting said upper chassis on said lower chassis.

3. A rotary automobile crane as described in claim 2,

ing means for said intermediate piece, comprising a resilient strut connected to said upper chassis, a frame having two struts connected with their respective lower ends to said intermediate piece and with their respective upper ends to said resilient strut, a pulley mounted at the top of said frame and connected to said hoisting line.

5. A rotary automobile crane as described in claim 4, further comprising control switch means adapted to switch on and off the driving means of the crane in i accordance'with the height of said rolls of said intermediate piece above said rails.

6. A rotary automobile crane as described in claim 2, wherein said supporting means comprise a plurality of rolls mounted on said intermediate piece at the end connected to said boom, and corresponding rails on said lower chassis adapted to receive said rolls.

7. A rotary automobile crane as described in claim 6, wherein said supporting means comprise a pair of platforms laterally extending at both longitudinal sides of said lower chassis, and rails on said platforms meeting said rail on said lower chassis and adapted to receive said rolls. t

8. A rotary automobile crane as described in claim wherein said supporting means further comprise support means mountedon said lower chassis and said platforms below said rails and adapted to support said lower chassis and said platforms on the floor.

9. A rotary automobile crane as described in claim 7, further comprising means for lifting said rolls on said intermediate piece from said rails and tensioning said intermediate piece so as to retain its position relative to said upper chassis. v

10. A rotary automobile crane as described in claim 6, further comprising means for adapting the height of said rolls to the load moment and for tensioning said intermediate piece so as to retain its position relative to said upper chassis.

References Cited in the file of this patent UNITED STATES PATENTS 755,644 Fairbanks Mar. 29, 1904 2,784,850 Batson Mar. 12, 1957 FOREIGN PATENTS 483,842 Great Britain Apr. 27, 1938 701,783 Germany Jan. 23, 1941 

